Ender 3 X-axis tensioner (for short belts)

cults3d

This tensioner is designed for a stock Ender 3 with a short belt (one without a lot of excess length). Every other x-axis tensioner I tried to print wouldn't allow the bearing to touch the extrusion end, by several mm. So I couldn't get my short stock x-axis belt to reconnect to the carriage. This remix allows the tension bearing to get all the way up against the extrusion, guarantying that you'll be able to get your belt re-attached. I also made the through-holes bigger than the ones in the source design to more accurately match the stock screw, and added insets for the screw head and end nut so you can use those instead of having to screw directly into the plastic. The nut recess isn't deep enough to hold it in place for tightening the screw, but the outer casing track is tight enough to do so during assembly/disassembly - so you only need a hex key. This design also has plenty of space to get the belt in and out, unlike some of the other designs I tried. Note that this design will only tension the belt up to a max of ~10mm away from the end of the extrusion, so it's not good for belts with a lot of excess length.